Encryption 2

An encryption key is used to help decrypt messages

• True
• False

Taking a secret message and reproducing the original plain text is known as?

• Vigenere Cipher
• Encryption
• Random Substitution cipher
• Decryption

What is the algorithm of ceasar's cipher?

• Each letter is replaced with a particular symbol

• Each letter is replaced with a letter a certain number of steps down the alphabet

• Each letter is replaced with a particular number from 0 to 26, and numbers are replaced with letters.

• Each letter is replaced with a completely random number

What is symmetric encryption?

• When users use the same key to encrypt communication.

• When users use the same line of communication.

• When users use the same operating systems.

• When users use the same font in messages

What type of key is not shared and computers cannot decrypt a message without it?

• Free key
• Private key
• Public key
• Personal key

What type of key can be freely shared with anyone so that they can encrypt a message?

• Personal key
• Private key
• Free key
• Public key

The process of converting plaintext to ciphertext.

• cryptography

• cyphertext

• decryption

• encryption

A string of text that has been converted to a secure form using encryption.

• encryption

• decryption

• ciphertext

• plaintext

hello has been encrypted with Caesar cipher to khoor. The key used was:

• abc

• 3

• 2

• xyz

Consider the process of encoding and decoding a message using the following Caesar cipher encoding scheme in which the plaintext and ciphertext alphabets are offset by four positions, as shown below:

^{Plaintext: a b c d e f g h i j k l m n o p q r s t u v w x y z}

^{Ciphertext: w x y z a b c d e f g h i j k l m n o p q r s t u v}

Which of the following encoded ciphertext strings decodes to an original plaintext message of "secret"?

• etsecr

• wigvix

• kwujwl

• oaynap